钒(Ⅴ)-向红菲咯啉的络合吸附波

Polarographic Adsorption Wave of Vanadium (Ⅴ)-Bathophenanthroline Complex

在ｐＨ４．０２的０．０２ｍｏｌ／Ｌ ＨＡｃ－ＮａＡｃ介质中，研究了钒（Ｖ）－向红菲咯琳（ＢＰＴ）的极谱行为。钒（Ｖ）－ＢＰＴ络合物在滴汞电极上于－０．３６ Ｖ（ｖｓ．ＳＣＥ）得到一良好的吸附还原波，在聚乙烯醇（ＰＶＡ）存在下，其二阶导数值与钒（Ｖ）浓度在 ５．０×１０－８～４．０ ×１０－６ ｍｏｌ／Ｌ范围内呈线性关系；检出限可达 ９．０×１０－９ ｍｏｌ／Ｌ。应用该法测定饮用水及碳素钢中微量钒，结果较好。讨论了ＰＶＡ的影响，探讨了络合物及其电极过程。

The polarographic behavior of Vanadium(Ⅴ)4,7-diphenyl-1, 10-bathophenanthroline (BPT) system at a drop mercury electrode was investigated in a buffer solution of 0. 02 mol/L HAc-NaAc(pH 4.02). The V(Ⅴ)-BPT complex produces a reduction peak at - 0.36 V(vs. SCE). In the presence of 1.2 ×10-3 % polyvinyl alcohol (PVA), the detection limit and the linear range of the single-sweep sec- and order derivative osillopolagraphic wave were 9. 0 × 10-9 mol/L and 5.0 × 10-8 － 4 .0×10-6 mol/L V (Ⅴ ), respectively. This method has been applied to the determination of bee V(Ⅴ) in samples of drinking water and carbon steel with satisfactory results. The effects of the concentration of PVA on Ip and Ep of the V(V )-BPT complex, the composition of V(V)-BPT complex and the mechanism of the electrode process were discussed.